I'm not sure Stachytarpheta cayennensis is the correct one, there's a lot of species in Brazil. I found one with leaves which look a perfect match but with no species and no flowers!
http://www.flickr.com/photos/p...
I don't think the leaves quite match Stachytarpheta cayennensis, nor do the flowers. On Myriam's plant the flower petals are not as rounded.
The list in Brazil..
Verbenaceae Stachytarpheta ajugifolia Schauer
Verbenaceae Stachytarpheta alata (Moldenke) S.Atkins
Verbenaceae Stachytarpheta almasensis Mansf.
Verbenaceae Stachytarpheta amplexicaulis Moldenke
Verbenaceae Stachytarpheta andersonii Moldenke
Verbenaceae Stachytarpheta angustifolia (Mill.) Vahl
Verbenaceae Stachytarpheta arenaria S.Atkins
Verbenaceae Stachytarpheta atriflora S.Atkins
Verbenaceae Stachytarpheta bicolor Hook.f.
Verbenaceae Stachytarpheta brasiliensis Moldenke
Verbenaceae Stachytarpheta bromleyana S.Atkins
Verbenaceae Stachytarpheta caatingensis S.Atkins
Verbenaceae Stachytarpheta candida Moldenke
Verbenaceae Stachytarpheta canescens Kunth
Verbenaceae Stachytarpheta cassiae S.Atkins
Verbenaceae Stachytarpheta cayennensis (Rich.) Vahl
Verbenaceae Stachytarpheta cearensis Moldenke
Verbenaceae Stachytarpheta coccinea Schauer
Verbenaceae Stachytarpheta commutata Schauer
Verbenaceae Stachytarpheta confertifolia Moldenke
Verbenaceae Stachytarpheta crassifolia Schrad.
Verbenaceae Stachytarpheta crassifolia subsp. abairensis S.Atkins
Verbenaceae Stachytarpheta crassifolia Schrad. subsp. crassifolia
Verbenaceae Stachytarpheta crassifolia subsp. minasensis S.Atkins
Verbenaceae Stachytarpheta crassifolia subsp. rotundifolia S.Atkins
Verbenaceae Stachytarpheta dawsonii Moldenke
Verbenaceae Stachytarpheta diamantinensis Moldenke
Verbenaceae Stachytarpheta discolor Cham.
Verbenaceae Stachytarpheta froesii Moldenke
Verbenaceae Stachytarpheta galactea S.Atkins
Verbenaceae Stachytarpheta ganevii S.Atkins
Verbenaceae Stachytarpheta gesnerioides Cham.
Verbenaceae Stachytarpheta gesnerioides Cham. subsp. gesnerioides
Verbenaceae Stachytarpheta gesnerioides var. glabra S.Atkins
Verbenaceae Stachytarpheta gesnerioides var. hirsuta S.Atkins
Verbenaceae Stachytarpheta glabra Cham.
Verbenaceae Stachytarpheta glandulosa S.Atkins
Verbenaceae Stachytarpheta glauca (Pohl) Walp.
Verbenaceae Stachytarpheta glazioviana S.Atkins
Verbenaceae Stachytarpheta guedesii S.Atkins
Verbenaceae Stachytarpheta harleyi S.Atkins
Verbenaceae Stachytarpheta hatschbachii Moldenke
Verbenaceae Stachytarpheta hirsutissima Link
Verbenaceae Stachytarpheta hispida Nees & Mart.
Verbenaceae Stachytarpheta integrifolia (Pohl) Walp.
Verbenaceae Stachytarpheta itambensis S.Atkins
Verbenaceae Stachytarpheta jamaicensis
Verbenaceae Stachytarpheta lactea Schauer
Verbenaceae Stachytarpheta lacunosa Schauer
Verbenaceae Stachytarpheta laevis Moldenke
Verbenaceae Stachytarpheta linearis Moldenke
Verbenaceae Stachytarpheta longispicata (Pohl) S.Atkins
Verbenaceae Stachytarpheta longispicata subsp. brevibracteata (Moldenke) S.Atkins
Verbenaceae Stachytarpheta longispicata (Pohl) S.Atkins subsp. longispicata
Verbenaceae Stachytarpheta longispicata subsp. minasensis S.Atkins
Verbenaceae Stachytarpheta longispicata subsp. ratteri S.Atkins
Verbenaceae Stachytarpheta longispicata var. andersonii (Moldenke) S.Atkins
Verbenaceae Stachytarpheta longispicata var. longipedicellata (Moldenke) S.Atkins
Verbenaceae Stachytarpheta longispicata var. parvifolia (Moldenke) S.Atkins
Verbenaceae Stachytarpheta lychnitis Mart.
Verbenaceae Stachytarpheta lythrophylla Schauer
Verbenaceae Stachytarpheta macedoi Moldenke
Verbenaceae Stachytarpheta martiana Schauer
Verbenaceae Stachytarpheta matogrossensis Moldenke
Verbenaceae Stachytarpheta maximiliani Schauer
Verbenaceae Stachytarpheta mexiae Moldenke
Verbenaceae Stachytarpheta microphylla Walp.
Verbenaceae Stachytarpheta monachinoi Moldenke
Verbenaceae Stachytarpheta mutabilis (Jacq.) Vahl
Verbenaceae Stachytarpheta pachystachya Mart. ex Schauer
Verbenaceae Stachytarpheta paraguariensis Moldenke
Verbenaceae Stachytarpheta piranii S.Atkins
Verbenaceae Stachytarpheta pohliana Cham.
Verbenaceae Stachytarpheta polyura Schauer
Verbenaceae Stachytarpheta procumbens Moldenke
Verbenaceae Stachytarpheta puberula (Moldenke) S.Atkins
Verbenaceae Stachytarpheta quadrangula Nees & Mart.
Verbenaceae Stachytarpheta radlkoferiana Mansf.
Verbenaceae Stachytarpheta radlkoferiana Mansf. subsp. radlkoferiana
Verbenaceae Stachytarpheta radlkoferiana var. lanata S.Atkins
Verbenaceae Stachytarpheta restingensis Moldenke
Verbenaceae Stachytarpheta reticulata Mart. ex Schauer
Verbenaceae Stachytarpheta rhomboidalis (Pohl) Walp.
Verbenaceae Stachytarpheta rupestris S.Atkins
Verbenaceae Stachytarpheta scaberrima Cham.
Verbenaceae Stachytarpheta schottiana Schauer
Verbenaceae Stachytarpheta sellowiana Schauer
Verbenaceae Stachytarpheta sericea S.Atkins
Verbenaceae Stachytarpheta sessilis Moldenke
Verbenaceae Stachytarpheta spathulata Moldenke
Verbenaceae Stachytarpheta spathulata subsp. mogolensis S.Atkins
Verbenaceae Stachytarpheta spathulata Moldenke subsp. spathulata
Verbenaceae Stachytarpheta speciosa Pohl ex Schauer
Verbenaceae Stachytarpheta sprucei Moldenke
Verbenaceae Stachytarpheta stanardii S.Atkins
Verbenaceae Stachytarpheta stannardii S.Atkins
Verbenaceae Stachytarpheta straminea Moldenke
Verbenaceae Stachytarpheta trispicata Nees & Mart.
Verbenaceae Stachytarpheta tuberculata S.Atkins
Verbenaceae Stachytarpheta villosa (Pohl) Cham.
Verbenaceae Stachytarpheta viscidula Schauer
